Lacewings

Lacewings (Order Neuroptera) are a relatively small group of insects with around 5000 different species worldwide and more than 600 species known from Australia.

They range in size from the minute "dusty-wings" (Family Coniopterygidae) with wingspans as small as 5 mm, to Australia’s largest, Heloclisus fulva, an inland antlion with a wingspan up to 15 cm. Lacewings have two pairs of delicate wings, usually with a dense network of veins. Most have a weak, floppy flight, but some such as owl flies and the uniquely Australian stilbopterygines (a special group of antlions) are fast, agile fliers that resemble dragonflies.

Australia’s largest group of lacewings are the antlions (around 250 species) which are particularly common in arid and semiarid areas. Adult and larval lacewings are mostly predators. Some groups such as green lacewings (Family Chrysopidae) and brown lacewings (Family Hemerobiidae) are beneficial in crops and gardens feeding on plant pests such as aphids, scale insects and moth eggs and caterpillars.

Adults of many lacewing species are active at night and often attracted to lights, but others are active during the day.

Stilbopteryx walkeri (Stilbopterygidae).

Mantid Lacewing (Austromantispa imbecilla).

Lacewings have an elongate, soft body and two pairs of similar-sized, transparent wings. They have a dense network of wing veins which often branch just before they reach the edges of the wings. Large lacewings can resemble dragonflies, but differ by the tent-like way they fold the wings over the abdomen when they are resting. The antennae of lacewings are much longer than those of dragonflies and they are often thickened at the tips into clubs.

The immature stages of lacewings are larvae which look very different from the adults. Most have enlarged, sickle-shaped jaws modified for piercing and sucking out the contents of their prey.

There are numerous families of lacewings including:

Mantid Lacewings (Family Mantispidae) have modified raptorial front legs, designed to capture and grasp prey, that look very similar to those of mantids.

Lacewings undergo abrupt metamorphosis usually with three larval stages in the life cycle. Many adult lacewings are predators of other insects but some feed on nectar and honeydew or other plant material. Lacewing larvae are mostly predators of other insects and many are voracious hunters. Other larvae employ a 'sit and wait' ambush strategy and include the familiar ant lions that construct conical pits to trap their prey. The larvae of Mantid Lacewings are grub-like parasites found inside spider egg sacs. Moth Lacewing (Family Ithonidae) larvae live underground and feed on decaying plant matter while the larvae of sponge-flies (Family Sisyridae) are aquatic and feed on freshwater sponges. Some lacewing larvae camouflage themselves by attaching debris, sometimes the empty husks of their prey, to their backs.

Osmylops larva (Family Nymphidae)

Head and jaws of an antlion larva (Family Myrmeleontidae). These larvae make conical pits to trap their prey.